The Nigerian candidate to head the World Bank, Ngozi Okonjo-Iweala, called Tuesday for emerging nations to have a greater voice in the running of the world economy. \"The world has changed over sixty years,\" the Nigerian finance minister told France\'s daily Le Monde, saying economic governance needs to change as well. She pointed to success of the G20, which groups the world\'s top industrialised and emerging nations. \"The BRICS account for more than half of global growth. Isn\'t it time to include them in the management of the world. I think the answer is yes,\" she said. The BRICS emerging nations powerhouses -- Brazil, Russia, India, China and South Africa -- so far have no plans to unite behind a single candidate to replace Robert Zoellick, who is stepping down at the end of his term on June 30. Under a tacit agreement since the World Bank and its sister institution the International Monetary Fund were founded, the United States always selects an American as World Bank president and Europe puts a European at the IMF helm. Developing and emerging economies have been increasingly unhappy with this arrangement and have been pushing for greater representation to reflect their rising contributions to the global economy. This time Washington\'s candidate to head up the World Bank, Korean-American physician Jim Yong Kim, known for his work in World Health Organization campaigns against AIDS in Africa, faces competition from Okonjo-Iweala and Jose Antonio Ocampo of Colombia. Okonjo-Iweala is a respected former World Bank managing director and Ocampo is a former finance minister and central bank chief. Okonjo-Iweala called on nations to honour their pledges to make the selection process transparent and on merit. The World Bank has 187 member nations and focuses its activities on development loans. The Washington-based lender is expected to select its new president \"by consensus\" by its 2012 Spring meetings that begin on April 20.